This invention relates to gas turbine engines in general and in particular to gas turbine engines having fluid cooled turbines.
In order to increase the power output and efficiency of gas turbines, it is desirable to operate such turbines at as high a turbine inlet temperature as possible. Presently these temperatures are limited to a range of 1800.degree. to 2000.degree. Fahrenhit, primarily because of temperature limitations of the metal alloys used in the rotating components. Higher inlet temperatures can be used if the turbine blades can be successfully cooled. In larger turbine engines air cooling of blades is successful, however, in small turbine engines the blades are of a substantially smaller size and do not provide sufficient metal thickness to allow air cooling passages of effective size.
Water cooling of turbine blades has been successful in the past in large stationary power generating plants. However, in order to avoid excessive water consumption it has been necessary to provide for condensation and recirculation of the cooling water. For small gas turbine engines, particularly in vehicle applications, the inclusion of such a condenser and recirculating system is impracticable.